Base on the theory of erosion dynamics,geomorphology,hydrology,mechanism of sediment transport,a distributed soil loss model was built and applied in Chabagou watershed in sandy areas of Yellow River by using GIS technique,the model could be used to count the amount of soil loss on watershed loess slope,gully and groove,the model is capable to coupling the runoff process and sediment transport;raised the concept of equivalence estimation roughness coefficient,preliminary solve the problem soil and water conservation project to change runoff,so the model could forecast the benefit on different control plan of soil and water conservation;the soil loss imitation forecast information were extracted use 3S technique;built the definition method of classification template in virtual reality environment to improve the classification precision of remote sensing image,prefect solve the problem to distinguish the phenomenon " the different thing with same spectrum and the same thing with different spectrum".Compare to the soil loss amount measured in Chabagou and Xingzihe watershed,the model could rightly to mirror the rule of watershed soil loss in Yellow River sandy areas.